Background

Pulmonary capillary wedge pressure (PCWP) plays a pivotal role in cardiac disease diagnosis and management. Right heart catheterization (RHC) invasively provides accurate PCWP measurement, but it is impractical for widespread use in all patients. The left atrial expansion index (LAEI), measured on transthoracic echocardiography, describes the relative left atrial volume increase during the left atrial reservoir phase. The aim of this study was to validate LAEI as a noninvasive parameter for PCWP estimation.

Methods

A total of 649 chronic cardiac patients (mean age, 66 ± 14 years; mean PCWP, 14 ± 7.6 mm Hg; mean left ventricular ejection fraction, 50 ± 15%) who underwent both clinically indicated RHC and transthoracic echocardiography within 24 hours were retrospectively enrolled. Patients were randomly divided into derivation (n = 509) and validation (n = 140) cohorts. PCWP was measured during RHC and defined as elevated when >12 mm Hg. Transthoracic echocardiographic parameters and LAEI were measured offline, blinded to RHC results.

Results

In the derivation cohort, LAEI correlated logarithmically with PCWP, and the log-transformed LAEI (lnLAEI) correlated linearly with PCWP (r = −0.73, P < .001). lnLAEI showed an independent and additive predictive role for PCWP estimation over clinical and diastolic dysfunction (DD) parameters. The diagnostic accuracy of lnLAEI for elevated PCWP identification (area under the curve = 0.875, P < .001; optimal lnLAEI cutoff < 4.02) was higher than either the single DD parameters or their combination. In the validation cohort, lnLAEI cutoff < 4.02 showed higher accuracy than the 2016 DD algorithm (88% vs 74%) for elevated PCWP identification. Finally, the equation PCWP = 38.3 − 6.2 × lnLAEI, obtained from the derivation cohort, predicted invasively measured PCWP in the validation cohort.

Conclusions

In a cohort of patients with various chronic cardiac diseases, lnLAEI performed better than DD parameters and the 2016 DD algorithm for PCWP estimation. lnLAEI might be a useful echocardiographic parameter for noninvasive PCWP estimation.

中文翻译：

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用于无创估计肺毛细血管楔压的左心房扩张指数：心导管验证研究

背景

肺毛细血管楔压 (PCWP) 在心脏病诊断和管理中起着举足轻重的作用。右心导管插入术 (RHC) 以侵入性方式提供准确的 PCWP 测量值，但在所有患者中广泛使用是不切实际的。经胸超声心动图测量的左心房扩张指数 (LAEI) 描述了左心房蓄水期的相对左心房容积增加。本研究的目的是验证 LAEI 作为 PCWP 估计的无创参数。

方法

共有 649 名慢性心脏病患者（平均年龄，66 ± 14 岁；平均 PCWP，14 ± 7.6 mmHg；平均左心室射血分数，50 ± 15%）在 24 小时内接受了有临床指征的 RHC 和经胸超声心动图检查。注册。患者被随机分为派生组 ( n  = 509) 和验证组 ( n  = 140)。在 RHC 期间测量 PCWP，当 >12 mm Hg 时定义为升高。经胸超声心动图参数和 LAEI 是离线测量的，对 RHC 结果不知情。

结果

在推导队列中，LAEI 与 PCWP 呈对数相关，对数转换后的 LAEI (lnLAEI) 与 PCWP 呈线性相关（r  = -0.73，P  < .001）。lnLAEI 显示出 PCWP 估计对临床和舒张功能障碍 (DD) 参数的独立和附加预测作用。lnLAEI 对升高的 PCWP 识别的诊断准确性（曲线下面积 = 0.875，P < .001; 最佳 lnLAEI 截止值 < 4.02）高于单个 DD 参数或其组合。在验证队列中，lnLAEI 截止值 < 4.02 显示出比 2016 年 DD 算法（88% 对 74%）更高的 PCWP 识别准确度。最后，从推导队列获得的方程 PCWP = 38.3 − 6.2 × lnLAEI 预测了验证队列中侵入性测量的 PCWP。

结论

在一组患有各种慢性心脏病的患者中，lnLAEI 在 PCWP 估计方面的表现优于 DD 参数和 2016 DD 算法。lnLAEI 可能是用于无创 PCWP 估计的有用的超声心动图参数。